Radio control helicopter toy

ABSTRACT

The present invention provides a radio control helicopter toy including a mast mounted projecting to the upper side of an airframe so as to be rotated by a main motor, a rotor mounted on the upper part of the mast via a rotor head with the blade surface of a rotor blade capable of inclining, a blade inclining mechanism having an arm with one end part side thereof mounted rotatably on the airframe side and the other end part side thereof is mounted to be driven to approach to the above-mentioned rotor head side by an actuator, for inclining the blade surface of the above-mentioned rotor by the magnetic force generated between magnets mounted on the end part of the arm and the above-mentioned rotor head or between a magnet and a ferromagnetic material, and a receiver loaded on the above-mentioned airframe for controlling the operation of the above-mentioned main motor and the actuator.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a radio control helicopter toy, themovement control thereof is performed with remote control.

2. Description of the Related Art

Conventionally, for the movement control of a helicopter, movement canbe made in front and back, right and left directions by inclining theblade surface of a rotor provided on the aircraft. For inclining theblade surface of such a rotor, in the real helicopter, a mechanism forinclining the blade surface by interlocking a swash plate, rotatingtogether with the rotor, with the blade via a link is adopted. This kindof the rotor blade surface inclining mechanism by a swash plate isadopted also for a movement control for a helicopter toy. For example, atechnique related to a radio control helicopter with co-axial rotors,that is upper and lower rotor heads rotating in the opposite directionsare provided concentrically, wherein the inclining of the blade rotationsurface is controlled by interlocking a blade of the lower rotor headwith a swash plate of a blade inclining mechanism provided in a aircraftis disclosed (for example, see Kokai (Jpn unexamined patent application)No. 2004-121798 (p. 3 to 6, FIGS. 1 to 7)).

Since the inside part of the conventional swash plate is connected withthe rotor head, which is rotating via a link, a structure allowing theinside part to always rotate together with the rotor head. However,since the outside part is connected with an actuator mounted on theairframe for controlling the inclining of the swash plate with a link,it cannot be rotated. Therefore, a highly sophisticated part such as aball bearing is required for the inside and the outside of the swashplate, and the structure is also complicated. Moreover, since the allparts from an actuator to the rotor head are connected via links, thestructure is extremely complicated as well as the number of parts islarge so that the cost may be increased as a whole.

SUMMARY OF THE INVENTION

The present invention has been achieved in view of the above-mentionedcircumstances, and an object thereof is to provide a radio controlhelicopter toy capable of providing a mechanism for the movement controlin a simple structure so as to be produced at low cost.

In order to achieve the above-mentioned object, a first aspect of thepresent invention includes: a mast mounted projecting to the upper sideof an airframe so as to be rotated by a main motor loaded on theairframe; a rotor mounted on the upper part of the mast via a rotor headwith the blade surface of a rotor blade capable of inclining; a bladeinclining mechanism having an arm with one end part side thereof mountedrotatably on the airframe side and the other end part side thereof ismounted to be driven to approach to the above-mentioned rotor head sideby an actuator loaded on the above-mentioned airframe, for inclining theblade surface of the above-mentioned rotor by the magnetic forcegenerated between magnets mounted on the end part of the arm and theabove-mentioned rotor head or between a magnet and a ferromagneticmaterial; and a receiver loaded on the above-mentioned airframe forcontrolling the operation of the above-mentioned main motor and theactuator. Since the rotor blade surface is inclined by the magneticforce, the conventional inclining mechanism by a swash plate can beeliminated so that the mechanism for the movement control can beprovided in a simple structure as well as it can be produced at lowcost.

In a second aspect of the present invention, the above-mentioned masthas an upper mast and a lower mast to be rotated concentrically in theopposite directions by the above-mentioned main motor; theabove-mentioned rotor has an upper rotor mounted on the upper part ofthe above-mentioned upper mast via an upper rotor head with the bladesurface of the upper rotor blade capable of inclining and a lower rotormounted on the upper part of the above-mentioned lower mast via a lowerrotor head with the blade surface of the lower rotor blade capable ofinclining; and the above-mentioned blade inclining mechanism is providedon the above-mentioned airframe for inclining the blade surface of theabove-mentioned lower rotor. In a helicopter toy having an upper mastand a lower mast to be rotated concentrically in the oppositedirections, the movement control mechanism can be provided in a simplestructure as well as it can be produced at low cost.

In the third aspect of the present invention, a stabilizer forcontrolling the flight attitude of the above-mentioned airframe ismounted on the above-mentioned upper mast so as to interlock with theabove-mentioned upper rotor head. According to the stabilizer, theattitude of the airframe can be maintained stably.

In the fourth aspect of the present invention, the above-mentioned bladeinclining mechanism has the above-mentioned arm to be driven by theactuator provided in for points of the front, back, right and leftaround the above-mentioned mast. With the masts in the four points, thedirection control in the frontward, backward, right and left directionscan be enabled.

In the fifth aspect of the present invention, a tail pipe is mounted onthe rear side of the above-mentioned airframe and a tail rotor to bedriven by a tail motor is mounted on an end part of the tail pipe. Withthe tail rotor, the airframe turnover can be prevented as well as theairframe can be controlled in the right and left directions.

In the sixth aspect of the present invention, the magnet or theferromagnetic material mounted on the above-mentioned rotor head of theabove-mentioned blade inclining mechanism is formed in a ring-like shapesurrounding the rotation center of the above-mentioned mast. Since themagnet or the ferromagnetic material mounted on the rotor head is formedin a ring-like shape, the blade surface inclination of the rotor bladecan be controlled certainly.

Since a mast mounted on the upper side of an airframe so as to berotated by a main motor loaded on the airframe, a rotor mounted on theupper part of the mast via a rotor head with the blade surface of arotor blade capable of inclining, a blade inclining mechanism having anarm with one end part side thereof mounted rotatably on the airframeside and the other end part side thereof is mounted to be driven toapproach to the above-mentioned rotor head side by an actuator loaded onthe airframe, for inclining the blade surface of the above-mentionedrotor by the magnetic force generated between magnets mounted on the endpart of the arm and the above-mentioned rotor head or between a magnetand a ferromagnetic material, and a receiver loaded on theabove-mentioned airframe for controlling the operation of theabove-mentioned main motor and the actuator are provided, the rotorblade surface can be inclined by the magnetic force so that themechanism for the movement control can be provided in a simple structureas well as it can be produced at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view for explaining the entire configuration ofa radio control helicopter toy of an embodiment of the presentinvention.

FIG. 2 is a perspective view for explaining a blade inclining mechanismof a radio control helicopter toy of the embodiment of the presentinvention.

FIG. 3 is a side view for explaining a blade inclining mechanism of aradio control helicopter toy of the embodiment of the present invention.

FIG. 4 is a perspective view of a blade inclining mechanism part of aradio control helicopter toy of the embodiment of the present invention.

FIG. 5 is a block diagram for explaining the control operation of aradio control helicopter toy of the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be explained specifically withreference to an embodiment shown in the figures. FIGS. 1 to 5 arediagrams for explaining a radio control helicopter toy of an embodimentof the present invention. FIG. 1 is a perspective view for explainingthe entire configuration of a radio control helicopter toy, FIG. 2 is aperspective view for explaining a blade inclining mechanism of a radiocontrol helicopter toy, FIG. 3 is a side view for explaining a bladeinclining mechanism of a radio control helicopter toy, FIG. 4 is aperspective view of a blade inclining mechanism part of a radio controlhelicopter toy, and FIG. 5 is a block diagram for explaining the controloperation of a radio control helicopter toy.

In these figures, the radio control helicopter toy 10 of this embodimentincludes an airframe 11, an upper rotor 12 and a lower rotor to berotated concentrically in the opposite directions, provided in the upperpart of the airframe, a stabilizer 14 for stably maintaining therotating attitude, interlocking with one of the rotors, a driving part15 loaded on the airframe 11 for rotating the upper rotor 12, the lowerrotor 13 and the stabilizer 14, a blade inclining mechanism 16 loaded onthe airframe 11 for controlling the moving direction by inclining theblade surface of the lower rotor 13, a tail rotor 17 mounted on the rearside of the airframe 11, a receiver 20 loaded on the airframe 11 forreceiving a control signal sent from a transmitter 19 and controllingthe operation of the driving part 15, the blade inclining mechanism 16and the tail rotor 17, a battery 18 loaded in the airframe 11 forsupplying the power source to each part, and the like.

The airframe 11 loads the above-mentioned parts, is formed with aplastic material, is formed in an arbitral shape modeled after ahelicopter, and is provided with a landing member 21 in the lower partfor landing in a stable state.

The upper rotor 12 includes an upper rotor head 25 mounted tiltably onthe upper end part side of an upper mast 23 rotatingly driven by thedriving part 15, and a pair of upper rotor blades 26, 26 mounted on bothend part sides of the upper rotor head 25. The upper rotor head 25shaped in a substantially rectangular ring-like shape slightly largerthan the outer diameter of the upper mast 23 is mounted tiltably on bothend parts of a driving shaft 27 provided in a direction orthogonal tothe rotation shaft center at the upper end part side of the upper mast23. The upper rotor blades 26, 26 are mounted on both end part sides ofthe upper rotor head 25 along the shaft center of the driving shaft 27for generating the lift up force at the time of being rotatingly drivenby the upper mast 23.

The stabilizer 14 includes a stabilizer head 28 mounted on the uppermast 23 on the lower side of the upper rotor 12, a pair of stabilizershafts 29, 29 mounted on both end faces of the stabilizer head 28,weights 30, 30 each mounted on end part sides of the stabilizer shafts,and a stabilizer link 32 mounted so as to interlock the stabilizer head28 and the upper rotor head 25. The stabilizer head 28 is formed in asubstantially rectangular ring-like shape slightly larger than the outerdiameter of the upper mast 23. The stabilizer head 28 is mountedtiltably on both end parts of a shaft 31 penetrating through the uppermast 23 in a direction orthogonal to the rotation shaft center of theupper mast 23 at the lower part side of the upper rotor head 25. Thestabilizer 14 is mounted such that the intersection angle the mountingdirection of the stabilizer shafts 29, 29 and the mounting direction ofthe upper rotor blades 26, 26 of the upper rotor 12 is for example aninclination angle of about 30 to 90 degrees. That is, according to thestabilizer 14, in the case the weights 30, 30 and the stabilizer shafts29, 29 are inclined to a certain direction around the shaft 31 togetherwith the stabilizer head 28, the upper rotor head 25 is interlocked andinclined around the driving shaft 27 via the stabilizer link 32accompanied by the inclination so that the surfaces of the upper rotorblades are inclined in the same direction.

The lower rotor 13 includes a lower rotor head 33 mounted tiltably onthe upper end part side of the lower mast 24 to be rotatingly driven bythe driving part 15, and a pair of lower rotor blades 34, 34 mounted onboth end part sides of the lower rotor head 33. The lower rotor head 33with the central part shaped in a substantially rectangular ring-likeshape slightly larger than the outer diameter of the lower mast 24 ismounted tiltably on the both end parts of a driving shaft 22 provided ina direction orthogonal to the rotation shaft center at the upper endpart side of the lower mast 24. The lower rotor head 33 has mountingparts 35, 35 formed with the both end face sides without having the pairof the lower rotor blades 34, 34 projecting downward. Ferromagneticmaterials 49, 49, consisting of small pieces to be attracted by amagnet, are mounted on the lower end parts of the mounting parts 35, 35.As to the inclination angle around the shaft center of the driving shaft22 of the lower rotor head 33, as it will be explained later in detail,even in the case the ferromagnetic materials 49, 49 are attracted by amagnetic force, they do not come in contact with the blade incliningmechanism 16. The lower rotor blades 34, 34 are mounted on the both endpart sides of the lower rotor head 33 along the shaft center directionof the driving shaft 22 so as to generate the lift up force at the timeof being rotatingly driven by the lower mast 24.

The upper mast 23 is formed with a slightly thick shaft part on theupper side on which, the upper rotor 12 and the stabilizer 4 aremounted, and with a narrow shaft part on the lower side. The lower mast24 is formed in a substantially pipe-like shape such that the narrowshaft part on the lower side of the upper rotor 12 is rotatablyintroduced through the pipe. The upper mast 23 and the lower mast 24 aremounted through from the central upper part to the inside of theairframe 11 so as to be rotated at the same rate in the oppositedirections by the driving part 15.

The driving part 15, disposed in the airframe 11 on the lower side ofthe upper mast 23 and the lower mast 24, includes a main motor 36, apinion 37, a lower main gear 38 and an upper main gear 39 having thesame number of teeth, and an inversion gear pair 40 to be rotated in theopposite directions at the same rate. The main motor 36 is mounted onthe airframe 11 with the driving shaft oriented upward, and the pinion37 is mounted on the driving shaft. The lower main gear 38 is mounted onthe lower end part side of the narrow shaft part on the lower side ofthe upper mast 23, and the upper main gear 39 is mounted on the lowerend part side of the lower mast 24. The lower main gear 38 is engagedwith the pinion to be rotated by the main motor 36. The lower main gear38 is engaged with one of the gears of the inversion gear pair 40, andthe other gear of the inversion gear pair 40 is engaged with the uppermain gear 39. That is, the rotational force by the main motor 36 istransmitted to the lower main gear 38 via the pinion 37, and then istransmitted to the upper main gear 39 via the inversion gear pair 40from the lower main gear 38 so that the upper mast 23 and the lower mast24 are rotated in the opposite directions.

The blade inclining mechanism 16, for the movement control by incliningthe lower rotor blade 34, 34 surfaces by the magnetic force via thelower rotor head 33 mounted tiltably on the upper end part side of thelower mast 24, includes an actuator 41, a rotation plate 42, a pair ofarm supporting parts 43, 43, arms 44, 44, links 45, 46, 47, and magnets48, 48. The actuator 41 is mounted on the front part side airframe 11 onthe lower side of the lower rotor 13 with the driving shaft oriented tothe horizontal direction. The rotation plate 42 is mounted on thedriving shaft of the actuator 41. The arm supporting parts 43, 43 aremounted on the front and rear parts of the airframe 11 across the lowerpart side of the lower mast 24 respectively. To each of the armsupporting parts 43, 43, one end parts of the arms 44, 44 formed in arod-like shape, for example, are mounted rotatably, and the other endpart sides are oriented to the lower part side of the upper lower rotorhead 33. The magnets 48, 48 are mounted on the other end parts orientedupward of these arms 44, 44, respectively. The rotation plate 42 mountedon the driving shaft of the actuator 41 and one of the arms 44 in frontare interlocked with the link 45. The arm 44 in front and the arm 44 inrear are interlocked with the links 46, 47. The blade incliningmechanism is for rotating the rotation plate 42 by the actuator 41, androtating the arms 44, 44 with the arm supporting parts 43, 43 providedas the supporting points via the links 45, 46, 47. That is, by the driveof the actuator 41, the arm 44 in front is rotated from the slightlyinclined neutral position to make the magnet 48 approach to theferromagnetic material 49 side of the mounting part 35 of the lowerrotor head 33. Then, by the magnetic force, the lower rotor head 33 isattracted and rotated so as to incline the surfaces of the lower rotorblades 34, 34 forward. On the other hand, the arm 44 in rear is rotatedfrom the slightly inclined neutral position to make the magnet 48approach to the ferromagnetic material 49 of the mounting part 35 of thelower rotor head 33. Then, by the magnetic force, the lower rotor head33 is attracted and rotated so as to incline backward the surfaces ofthe lower rotor blades 34, 34 backward. In the case the arms 44, 44 areboth at the slightly inclined neutral position, it is a position withoutthe function of the magnetic force so as not to rotate the lower rotorhead 33. In the case one of the arms 44 is rotated form the neutralposition to a position close to the lower part side of the lower rotorhead 33, the magnetic force is applied, however, the other arm 44 isfurther inclined form the neutral position so as to rotate to a positionwithout the function of the magnetic force. Since the lower rotor head33 is arranged not to be incline to more than a certain angle, either ofthe magnets 48, 48 approaches to the ferromagnetic materials 49, 49without contacting thereto and it is rotated with the lower mast.

In this embodiment, since the upper rotor 12 and the lower rotor 13 tobe rotated concentrically in the opposite directions are provided, thetail rotor 17 needs not be rotated for preventing turnover of theairframe 11, however, the tail rotor 17 is mounted rotatably on a tailpart 50 provided on the end part of the tail pipe 49 elongatinghorizontally from the rear part of the airframe 11. The tail rotor 17 isarranged to be transmitted the rotational force of the tail motor 51provided in the rear part of the airframe 11 via the driving shaftprovided inside the tail pipe 49, the bevel gear provided in the tailpart 50, or the like. By rotating the tail rotor 17 forward or backwardby the tail motor 51, the airframe 11 is rotated around the shaft centerof the upper mast 23 and the lower mast 24, and thereby the operationcontrol in the right and left direction can be enabled.

The receiver 20 includes an antenna 61, a receiving circuit 62 forreceiving a control signal as a radio wave transmitted from thetransmitter 19, a control circuit 63 for producing a control signalbased on the signal received by the receiving circuit 62, a motordriving circuit 64 for driving the main motor 36 and the tail motor 51based on the control signal of the control circuit 63, an actuatordriving circuit 65 for driving the actuator 41, and the like such thatthe electric power from the battery 18 can be supplied by a power sourceswitch 66 mounted operatably on the airframe 11, or the like to thereceiving circuit 62, the control circuit 63, the motor driving circuit64 and the actuator driving circuit 65. The transmitter 19 includes acontrol part 52 having a control lever for the orientation control forelevation, descent, forward or backward movement and the like, a signalproducing circuit 53 for producing a control signal according to theoperation of the control part 52, a transmitting circuit 54 fortransmitting a control signal produced by the signal producing circuit53 as a radio wave from the antenna 57, and the like such that theelectric power is supplied from the battery 55 by the power sourceswitch 56 to the signal producing circuit 53 and the transmittingcircuit 54.

The operation of the radio control helicopter toy 10 of theabove-mentioned configuration will be explained. First, by switching onthe power source switch 66 and placing the airframe 11 at a horizontalportion using the landing member 21, the radio control helicopter toy 10is prepared for taking off. Next, by switching on the power sourceswitch 56 of the transmitter 19 and operating the control lever of thecontrol part 52, a control signal based on the operation is produced inthe signal producing circuit 53 and the control signal is transmitted asa radio wave from the transmitting circuit 54 via the antenna 57. Thecontrol signal transmitted from the transmitter 19 is received by thereceiving circuit 62 via the antenna 61 of the receiver 20 provided inthe airframe 11 of the radio control helicopter toy 10. The controlsignal from the transmitter 19 received by the receiving circuit 62 istransmitted to the control circuit 63 so as to produce an output signal,and the output signal is outputted to the motor driving circuit 64 so asto produce a motor driving signal in the motor driving circuit 64 sothat the main motor 36 or the tail motor 51 starts the rotation based onthe motor driving signal. The rotational force of the main motor 36 istransmitted from the pinion 37 to the upper mast 23 via the lower maingear 38, and from the lower main gear 38, the rotation force is alsotransmitted to the lower mast 24 via the inversion gear pair 40 and theupper main gear 39 so as to rotate the upper rotor 12 and the lowerrotor 13 by the same rotational frequency in the opposite directionsrespectively. Thereby, the upper rotor blades 26, 26 mounted on theupper rotor head 25 of the upper rotor 12 and the lower rotor blades 34,34 mounted on the lower rotor head 33 of the lower rotor 13 arerespectively rotated so as to enable the ascending flight of theairframe 11. At the time, since the upper rotor 12 and the lower rotor13 are rotated at the same rotational rate in the opposite directions,the respective reaction torques applied to the airframe 11 can be offsetwith each other so that the airframe 11 can ascend without rotation.Moreover, since the stabilizer 14 mounted on the upper mast 23 isinterlocked with the upper rotor 12 via the stabilizer link 32, when thestabilizer shafts 29, 29 are rotated in a horizontal attitude, thestabilizer shafts 29, 29 continue stable operation while maintaining thehorizontal attitude due to the centrifugal force of the weights 30, 30.Moreover, in the case the stabilizer shafts 29, 29 are inclined from thehorizontal attitude for any reason, the stabilizer shafts 29,29 affectsthe surfaces of the upper rotor blades 26, 26 to be inclined in the samedirection via the stabilizer link 32 so that the function of maintainingthe surfaces of the upper rotor blades 26, 26 horizontally is generatedautomatically by the centrifugal force of the weights 30, 30. Therefore,the stable operation can be enabled while maintaining the attitude ofthe airframe 11.

Next, the operation of the movement control of the airframe 11 by theblade inclining mechanism 16 after ascending in the air to apredetermined height will be explained. First, when a control signal istransmitted by the forward operation from the transmitter 19, thereceiver 20 receives the forward control signal so that the forwardsignal is transmitted form the actuator driving circuit 65 to theactuator 41. When the actuator 41 receives the forward signal, therotation plate 42 is driven so as to rotate the arm 44 in front from theneutral position via the link 45 to make the magnet 48 approach to theferromagnetic material 49 side of the mounting part 35 of the lowerrotor head 33. Then, by the magnetic force, the lower rotor head 33 isattracted and rotated so as to incline the surfaces of the lower rotorblades 34, 34 forward. According to the forward inclination of thesurfaces of the lower rotor blades 34, 34, the airframe 11 can be movedforward. In the same manner, when a control signal is transmitted by thebackward operation from the transmitter 19, the rotation plate 42 isdriven so as to rotate the arm 44 from the neutral position via thelinks 45, 46, 47 to make the magnet 48 approach to the ferromagneticmaterial 49 side of the mounting part 35 of the lower rotor head 33.Then, by the magnetic force, the lower rotor head 33 is attracted androtated so as to incline the surfaces of the lower rotor blades 34, 34backward. According to the backward inclination of the surfaces of thelower rotor blades 34, 34, the airframe 11 can be moved backward. Inthis embodiment, by rotating forward or backward the tail rotor 17 bythe tail motor 51, the airframe 11 is oriented in the right or leftdirection with respect to the rotation shaft center of the upper mast 23and the lower mast 24, and thereby, the moving direction can becontrolled in the right and left direction.

As heretofore explained, according to the radio control helicopter toy10 of the embodiment of the present invention, since the surfaces of thelower rotor blades 34, 34 of the lower rotor 13 to be rotated by thelower mast 24 are inclined to the moving direction by attracting usingthe magnetic force by the blade inclining mechanism 16 mounted on theairframe 11, it can be produced in a simple structure at low costwithout the need of a swash plate or a link of a complicated structureas in the conventional configuration.

In the radio control helicopter toy 10 of the above-mentionedembodiment, moving direction can be controlled in forward and backwarddirection. However, the moving direction can be controlled also in rightand left direction by additionally providing a blade incliningmechanism, for inclining the surfaces of the lower rotor blades 34, 34in the right and left direction utilizing the magnetic force, to theairframe 11. Moreover, although an example of mounting the ferromagneticmaterials 49, 49 to the mounting parts 35, 35 of the lower rotor head 33and mounting the magnets 48, 48 on the end parts of the arms 44, 44 ofthe blade inclining mechanism 16 has been explained in this embodiment,as long as they are attracted by the magnetic force, either one can beferromagnetic material and the magnet, or furthermore, both of them canbe a magnet. Furthermore, the ferromagnetic material or the magnet to bemounted on the lower side of the lower rotor head 33 may be formed in aring-like shape instead of a small piece.

Furthermore, although a helicopter toy of a mechanism having the upperrotor 12 and the lower rotor 13 to be rotated concentrically in theopposite directions has been explained in this embodiment, as anotherembodiment, by mounting a blade inclining mechanism 16, with the samemechanism on one rotor to be driven in one direction by a main motor toan aircraft and applying the resultant mechanism to a radio controlhelicopter toy of a mechanism rotating the tail rotor 17. Moreover, thetail motor 51 can be mounted to the tail part 50 as well.

The present invention can be utilized for a radio control helicopter toyto have the movement control by the remote control.

1. A radio control helicopter toy comprising: a mast mounted projecting to the upper side of an airframe so as to be rotated by a main motor loaded on the airframe; a rotor mounted on the upper part of the mast via a rotor head with the blade surface of a rotor blade capable of inclining; a blade inclining mechanism having an arm with one end part side thereof mounted rotatably on the airframe side and the other end part side thereof is mounted to be driven to approach to the rotor head side by an actuator loaded on the airframe, for inclining the blade surface of the rotor by the magnetic force generated between magnets mounted on the end part of the arm and the rotor head or between the a magnet and a ferromagnetic material; and a receiver loaded on the airframe for controlling the operation of the main motor and the actuator.
 2. The radio control helicopter toy according to claim 1, wherein the mast has an upper mast and a lower mast to be rotated concentrically in the opposite directions by the main motor; the rotor has an upper rotor mounted on the upper part of the upper mast via an upper rotor head with the blade surface of the upper rotor blade capable of inclining and a lower rotor mounted on the upper part of the lower mast via a lower rotor head with the blade surface of the lower rotor blade capable of inclining; and the blade inclining mechanism is provided on the airframe for inclining the blade surface of the lower rotor.
 3. The radio control helicopter toy according to claim 2, wherein a stabilizer for controlling the flight attitude of the airframe is mounted on the upper mast so as to interlock with the upper rotor head.
 4. The radio control helicopter toy according to claim 1 or 2, wherein the blade inclining mechanism has the arm to be driven by the actuator provided in four points of the front, back, right and left around the mast.
 5. The radio control helicopter toy according to claim 1, wherein a tail pipe is mounted on the rear side of the airframe and a tail rotor to be driven by a tail motor is mounted on an end part of the tail pipe.
 6. The radio control helicopter toy according to claim 1, wherein the magnet or the ferromagnetic material mounted on the rotor head of the blade inclining mechanism is formed in a ring-like shape surrounding the rotation center of the mast. 